Concomitant with?DNA?replication, the chromosomal cohesin complex establishes?cohesion?between newly replicated?sister?chromatids. Several?replication-fork-associated "cohesion?establishment?factors," including the multifunctional Ctf18-RFC complex, aid this process in as yet unknown ways. Here, we show that Ctf18-RFC's role in?sister?chromatid?cohesion?correlates with?PCNA?loading but is separable from its role in the?replication?checkpoint. Ctf18-RFC loads?PCNA?with a slight preference for the leading strand, which is dispensable for?DNAreplication. Conversely, the canonical Rfc1-RFC complex preferentially loads?PCNA?onto the lagging strand, which is crucial for?DNAreplication?but dispensable for?sister?chromatid?cohesion. The downstream effector of Ctf18-RFC is cohesin acetylation, which we place toward a late step during?replication?maturation. Our results suggest that Ctf18-RFC enriches and balances?PCNA?levels at the?replicationfork, beyond the needs of?DNA?replication, to promote?establishment?of?sister?chromatid?cohesion?and possibly other post-replicative processes.